Optimisation of oxygenation and tissue perfusion in surgical patients

Improving Compliance With Valid Oxygen Prescriptions for Surgical Inpatients in a District General Hospital: A Single-Centre Quality Improvement Study

Introduction Medical oxygen is a drug and, as such, must be correctly prescribed according to British Thoracic Society (BTS) guidelines. These guidelines state that a valid prescription must include a target oxygen saturation range, and that all inpatients should have a valid oxygen prescription. A 2008 BTS audit revealed only 32% of patients receiving oxygen had valid prescriptions, and a 2015 re-audit showed improvement to 57.5%, still below the national 95% target. Unregulated oxygen administration can lead to complications such as hypoxia, hyperoxia, and increased healthcare costs. Our quality improvement project (QIP) aimed to improve adherence to BTS guidelines on two general surgical wards at Royal Blackburn Teaching Hospital, aiming for complete adherence. Methods A quality improvement study was conducted using electronic patient records (EPRs). In the baseline audit, data was collected on patients over a one-week period. Thirty-three patients were included, with information on age, oxygen prescriptions, and Chronic Obstructive Pulmonary Disease (COPD) status recorded. Four interventions were then implemented: the addition of reminders to handover sheets, visual prompts around the ward, announcements during nursing huddles, and WhatsApp reminders to the ward doctors. A re-audit was conducted after the interventions, including 31 patients, and data was compared using the Chi-squared test. Results In the baseline audit, 18% of patients had oxygen prescribed. Following the interventions, this rose to 54.8% (χ²(1, N=64) = 9.3, p < 0.01), and as such, was statistically significant. Among patients requiring oxygen, compliance improved from 0% to 90.9%.  Discussion The interventions significantly improved oxygen prescription compliance, demonstrating the effectiveness of simple, targeted measures. The inclusion of the multidisciplinary team (MDT) was crucial, as both nurses and doctors play essential roles in oxygen delivery. However, compliance remained below the BTS target of 100%. Limitations include not assessing the impact of individual interventions and analyzing only two points in time. Future audits should focus on targeting prescribers early in admissions and integrate electronic systems for automated prescription prompts. Spot audits could help ensure long-term success. Conclusion This QIP improved compliance with BTS oxygen prescribing guidelines at Royal Blackburn Teaching Hospital, from 18% to 54.8%. Engaging the MDT and using reminders increased compliance, but further efforts are needed to achieve the 100% target. Future interventions should focus on EPR integration, ongoing education, and further audit cycles for sustained improvement.

Clinical review: What are the best hemodynamic targets for noncardiac surgical patients?

Perioperative hemodynamic optimization, or goal-directed therapy (GDT), has been show to significantly decrease complications and risk of death in high-risk patients undergoing noncardiac surgery. An important aim of GDT is to prevent an imbalance between oxygen delivery and oxygen consumption in order to avoid the development of multiple organ dysfunction. The utilization of cardiac output monitoring in the perioperative period has been shown to improve outcomes if integrated into a GDT strategy. GDT guided by dynamic predictors of fluid responsiveness or functional hemodynamics with minimally invasive cardiac output monitoring is suitable for the majority of patients undergoing major surgery with expected significant volume shifts due to bleeding or other significant intravascular volume losses. For patients at higher risk of complications and death, such as those with advanced age and limited cardiorespiratory reserve, the addition of dobutamine or dopexamine to the treatment algorithm, to maximize oxygen delivery, is associated with better outcomes.

Maintaining tissue perfusion in high-risk surgical patients: a systematic review of randomized clinical trials

BACKGROUND

Surgical patients with limited organic reserve are considered high-risk patients and have an increased perioperative mortality. For this reason, they need a more rigorous perioperative protocol of hemodynamic control to prevent tissue hypoperfusion. In this study, we systematically reviewed the randomized controlled clinical trials that used a hemodynamic protocol to maintain adequate tissue perfusion in the high-risk surgical patient.

METHODS

We searched MEDLINE, Embase, LILACS, and Cochrane databases to identify randomized controlled clinical studies of surgical patients studied using a perioperative hemodynamic protocol of tissue perfusion aiming to reduce mortality and morbidity; the latter characterized at least one dysfunctional organ in the postoperative period. Pooled odds ratio (POR) and 95% confidence interval (CI) were calculated for categorical outcomes.

RESULTS

Thirty-two clinical trials were selected, comprising 5056 high-risk surgical patients. Global meta-analysis showed a significant reduction in mortality rate (POR: 0.67; 95% CI: 0.55-0.82; P < 0.001) and in postoperative organ dysfunction incidence (POR: 0.62; 95% CI: 0.55-0.70; P < 0.00,001) when a hemodynamic protocol was used to maintain tissue perfusion. When the mortality rate was >20% in the control group, the use of a hemodynamic protocol to maintain tissue optimization resulted in a further reduction in mortality (POR: 0.32; 95% CI: 0.21-0.47; P < 0.00,001). Monitoring cardiac output with a pulmonary artery catheter and increasing oxygen transport and/or decreasing consumption also significantly reduced mortality (POR: 0.67; 95% CI: 0.54-0.84; P < 0.001 and POR: 0.71; 95% CI: 0.57-0.88; P < 0.05, respectively). Therapy directed at increasing mixed or central venous oxygen saturation did not significantly reduce mortality (POR: 0.68; 95% CI: 0.22-2.10; P > 0.05). The only study using lactate as a marker of tissue perfusion failed to demonstrate a statistically significant reduction in mortality (OR: 0.33; 95% CI: 0.07-1.65; P > 0.05).

CONCLUSIONS

In high-risk surgical patients, the use of a hemodynamic protocol to maintain tissue perfusion decreased mortality and postoperative organ failure. Monitoring cardiac output calculating oxygen transport and consumption helped to guide therapy. Additional randomized controlled clinical studies are necessary to analyze the value of monitoring mixed or central venous oxygen saturation and lactate in high-risk surgical patients.

Monitoring oxygen transport and tissue oxygenation

PURPOSE OF REVIEW

To review recent publications in the field of oxygen delivery and tissue oxygenation. With few exceptions, we restricted our selection to clinical studies published in the English literature.

RECENT FINDINGS

No major breakthroughs have occurred in the past decade in the diagnosis or treatment of tissue hypoxia. There is renewed interest in goal-directed resuscitation when applied early in the course of treatment. Monitoring metabolic markers of tissue hypoxia continues to hold great clinical interest, in particular, tissue PCO2, near infrared spectroscopy, base deficit and blood lactate concentration. Technical issues, however, seem to restrict the widespread use of many of these techniques.

SUMMARY

There is an urgent need to develop methods to accurately and rapidly identify patients with tissue hypoxia. Perhaps the combination of gastric tonometry, near-infrared spectroscopy, urinary PO2 and continuous measures of mixed (or central) venous O2 saturation may provide the answer. An even more formidable task is that of developing effective therapy to correct tissue hypoxia while avoiding harm to the patient.

Postoperative Gastrointestinal Tract Dysfunction

Postoperative gastrointestinal (GI) tract dysfunction (PGID) is common and is associated with increased patient suffering and cost of care. The pathogenesis of PGID is complex and multifactorial. Traditional measures intended to reduce the incidence of PGID, such as the use of prokinetic drugs, nasogastric tube drainage, and the avoidance of early fluid and/or food intake, are apparently not beneficial. The administration of larger volumes of IV fluids to achieve predetermined increases in cardiac output has been shown in randomized trials to improve gut perfusion and reduce the incidence of PGID. A multimodal approach that includes limited surgical incision, regional local anesthesia, early mobilization, and enteral feeding has been associated with a dramatic reduction in postoperative complications, PGID, and length of hospital stay. However, none of these approaches has been validated in adequately powered multicenter prospective randomized controlled trials.